Palaeoenvironmental reconstruction through phytolith analysis in the Casa de Pedra shell mound archaeological site, São Francisco do Sul, Santa Catarina, Brazil

Shell mounds, or middens, are artificial accumulations of food remains such as shells, sediments, artefacts and remains from daily life and funerary rituals, which were deposited in our study area by groups of Sambaquian fisher-hunter-gatherers. These mounds contain remains, which are representative of the fauna and flora at the time they were formed, enabling the recovery of palaeoenvironmental data related to biodiversity of taxa and biogeography, 14 C dating and analysis of changes in the patterns of marine biodiversity and ocean circulation. This paper uses the Casa de Pedra shell mound rock shelter, located in São Francisco do Sul, state of Santa Catarina, southeastern Brazil, to study aspects of the palaeoenvironment through analyses of the archaeological material of the site, which contains well-preserved phytoliths and sponge spicules. Among the phytoliths, those from grasses predominate and some trees and palms were present, with no variation in vegetation type during the period of site occupation, between 5,470 and 4,460 years bp . Despite the general stability of the vegetation, a small increase in the density of the tree cover was identified from the base to the top, which may be related to an increase in precipitation, and is in agreement with other palaeoenvironmental studies carried out in southern Brazil.